Interiors of vehicles, which are subjected to high solar radiation, heat up, due to absorption of incident components in the infrared wavelength region of the solar radiation. Pigments which reflect the infrared radiation are incorporated into these surfaces of the interiors, in order to minimise the heating of these surfaces. This procedure however is disadvantageous inasmuch as such large quantities of infrared-reflecting pigments must be incorporated, that the colour spectrum is limited. In particular, it is hardly possible to realise dark colours.